The rules of engagement on LinkedIn are fairly clear: first and foremost, you should only connect with people you actually know. Yet millions of people—yes, we’re looking at you—are broadening their networks by connecting to people with whom they’ve never even had a discussion.

The rules of engagement on LinkedIn are fairly clear: first and foremost, you should only connect with people you actually know. Yet millions of people—yes, we’re looking at you—are broadening their networks by connecting to people with whom they’ve never even had a discussion.